I was trying to take out some old rad valve tails yesterday to fit TRVs. They are 3/4" with the rounded union and the TRVs are 15mm. The old tails have two "nibs" inside rather than a hex. In the past I have been able to get then out with my radiator key (like a big allen key) using the short end which has a square intended for taking out bleed plugs. The long arm has grooves in it that look as if they are supposed to fit the nibs, but won't go in. Presumably the wrong size.
Even when I took the rad off, and knelt on it on the floor to get more purchase, I couldn't shift them. Eventually I broke the corner off my rad key. I tried a socke set ratchet handle, 3/8" was too small and 1/2" too big. Is there a better tool that I can get? I was considering an allen key that fits the socket set and would be better steel than the rad key. Is there a proper tool made?
Even when I took the rad off, and knelt on it on the floor to get more purchase, I couldn't shift them. Eventually I broke the corner off my rad key. I tried a socke set ratchet handle, 3/8" was too small and 1/2" too big. Is there a better tool that I can get? I was considering an allen key that fits the socket set and would be better steel than the rad key. Is there a proper tool made?